Carburetor



Oct. 18, 1938.

F. EjsMrr 2,133,757

CARBURETOR Filed May 27, 1937 3 Sheets-Sheet l Fifi .61

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ATTORNEYS Oct. 18, 1938. F. E. SMITH 2,133,751 CARBURETOR Filed May 27, 1937 3 Sheets-Sheet 2 fi 2-. 20 I8 I 7V3 o 9;?

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BY wyzw lz ATTORNEYS Oct. 18, 1938. SMITH 2,133,757

CARBURETOR Fild Ma -27, 1937 3 Sheets-Sheet 3 ATTORNEY 9 Patented Oct. 18, 1938 2,133,757

UNITED STATES PATENT OFFICE 2,133,757 GARBURETOR Floyd E. Smith, Hapeville, Ga. Application May 27, 1937', Serial No. 145,107 2 claims. (01. 261 -18) This invention relates to a Carburetor espe- Integral with and surrounding the mixing chain ia ly adapt d f r internal ustion en ines her is a heating chamber 2 and also positioned and has for the primary object the provision of in the mixing chamber is a low grade fuel noza device of this character which will efii'ciently zle 3. One end of the chamber I is connected 5- vaporize or render crude fuel Volatile and pron onto a fitting 4 to provide an air intake and in 5 erly mix the same with air to produce a fuel for which operates a choke valve 5 of the butterfly an internal combustion engine whereby max'i-' type. An ordinary air cleaner may be connected mum power may be had from the engine at a low onto the fitting 4, as indicated by dotted lines cost and reduce the formation of carbon to a in Figure 1. The mixing chamber l is disposed minimum. I vertically with the fitting 4 positioned upper 10 Another object of this invention is the pro most. The lower end of the mixing chamber I vision of a device of the' above stated character is fitted on a sleeve 6 which in reality forms a which has means for utilizing a high grade fuel continuation of the mixing chamber l. A fitting for the starting and running of an engine at 1 connects with the lower end of the sleeveG. h

" idling speed and until sufficient heat is obtained The fitting forms a connection between the 15' to bring about vaporization of the low grade sleeve 6 and intake manifold In which forms fuel to permit the operation of the engine there an integral part of a stove 9. The intake manifrom at speeds faster than idling speed. fold stove 9 isshaped to enclose the major por With these and other objects in view, this intionof the intake manifold l0 andis provided n 26 vention consists in certain novel features of conwith a connecting neck II which may be constiuction, combination and arrangement of parts nec'tfed with an exhaust pipe (not shown) of the to be hereinafter more fully described and engine so that exhaust from the engine may claimed. pass into the stove 9 for heating the intake For a complete understanding of my inven manifold to a maximum temperature. The con tion, reference is to be had to the following necting neck II is in the form ofa fitting de- 25 description and accompanying drawings, in tachably secured o'ntoythe stove and has exhaust which I passages l2 and I3 communicative with each Figure 1 is a side elevation, partly in section, other by a port I4 controlled by a valve l5. The illustrating a carburetor constructed in accord--' exhaust passage l2 delivers exhaust into the stove ance with my invention. 9 while the passage 13 connects with an auxiliary 30" Figure 2 is a top plan view partly in section passage l6 formed in the stove and which opens illustrating the same. outwardly through one wall of said stove in the Figure 3 is a sectional view taken on the line form of apipe [1. The outer end of the ex- 3- 3' of Figure 1. haust passage I3 of the fitting is adapted to Figure 4 is a fragmentary vertical sectional be connected to the exhaust pipeiof the engine 35" view illustrating the low grade fuel jet and a for returning exhaust to said exhaust pipe. The choke operating in conjunction therewith for major portion of the intake manifold I0 is con controlling the supply of air. fined in the stove 9 and is provided with a plu.-'

Figure 5 is a detail sectional view showing rality of discharge necks I-8 adapted for connec 46*the combined air and high grade fuel control tion onto. the intake ports of the engine (not 40* device. I I 7 shown-) and which intake ports lead to the firing Figure 6 is a sectional view taken on the line chambers of the engine. (i=6 of Figure 4. Connecting on the stove 9 adjacent its ends Figure] is a sectional view taken on the line are converging pipes I9 and which terminate in 1 of Figure 4. I

Figure 8 is a sectional view taken on the line one side of the heating chamber 2, the opposite 8- 8 of Figure 4. v I side of the heating chamber being in communica-.

Figure 9 is a side elevation, partly in section, tion Witha pipe 2| connecting with the pipe l'l. illustrating amodified form of my invention for Thus it will be seen that the exhaust enters the a single delivery neck 20 having connection with 45' the utilization of a high grade fuel. stove 9 by way of the passage l2 circulating about 56 Referring in detail to the drawings, the nu the intake manifold l9 and thence passing up mera'l 1 indicates a mixing chamber which, as wardly from the stove by way of the pipes 19- to shown in this instance, is of tubular formathe heating chamber 2 and thence through the tion. However, the chamber i may take on other pipes 21 and i1 and through the "passages l6 shapes without departing from this invention. and I3 back to the exhaust pipe of the engine. 55G

Therefore, it will be seen that the intake manifold I0 is heated to a high temperature and also the mixing chamber l, the intake manifold being heated to a higher temperature than the mixing chamber.

A conventional type of float controlled fuel bowl 22 is carried by and in direct contact with the heating chamber 2 so that fuel therein will be preheated prior to entering the mixing chamber I. A pipe 23 having a cutoff valve 24 therein is connected at one end to the bowl 22 and its opposite end is connected to the nozzle 3. The fuel nozzle 3 includes an L-shaped tube 25 in which one leg portion thereof is disposed vertically in the mixing chamber I, while the opposite leg extends through a, wall of the mixing chamber and has the fuel pipe 23 connected thereto. A low grade fuel is supplied to the bowl 22 in any well known manner and the height of the fuel in the bowl is governed by the float.

A nozzle head 25 of substantially inverted coniinto a screw threaded passage formed in the head and which communicates'with the vertical leg portion of the tube 25 and carries at its upper end a substantially conical-shaped head 29 spaced from the head 26. Ports 30 are formed in the.

tube 28 andcommunicate with thefuel pot or recess2'l. Fuel from the bowl 22 will pass into the pot or recess 21 by seeking its level, however, the upper edge of the pot or recess is slightly above the level of the fuel in the bowl 22 to' prevent the fuel from spilling over from the pot or recess 27. A plate 3| is mounted on the tube 28 and rests on the head 26, consequently overlying the pot or recess 21.. A plurality of radially arranged slots 32 is formed in the plate which slots open. outwardly through the edges of said plate and portions of said slots overlie-the pot or recess 21. A substantially conical-shaped member 33 is mounted on the tube 28 and rests on the plate and overlies the slots so that said slot s only open outwardly into the mixing chamber 2at the edges of said plate. The plate and its slots cooperate in defining a plurality of radially arranged jets for delivering fuel from the pot or recess 21 into the mixing chamber. The upper end of the member 33 has formed therein a fuel pot or recess 34 over which the head 29 lies, the lower face of said head rests on the upper end of the member 33. The upper end of the member 33 has grooves 35 formed therein opening through the outer walls of the member 33, The head 29 overlies the grooves so that they cooperate with the member 33 in forming jets for delivering fuel from the pot or recess 34 into the mixing chamber above the jets provided by the plate 3|. Therefore, it will be seen that the fuel nozzle has groups of superimposed jets. The substantially conical-shaped member 33 upon its outer faces is curved, as shown at A. The upper group of jets are located in a plane above the level of the fuel in the bowl 22 so that the fuel in order to escape to the mixing chamber by way of the upper group of jets must be raised in the tube by suction. This also applies in reference to the lower group of jets, however, the raising of the fuel to pass out of the lower group of jets will be much less than the upper group of jets. The conical-shaped head 26 has beveled faces B that extend outwardly and 75,;downwar-dly from the lower group of jets. The

the tube 28 by ports 35.

Slidably mounted in the mixing chamber I is a Venturi element 36 which cooperates with the nozzle 26 in controlling fuel therefrom and also acts as an air control valve. The Venturi element controls the speed of operation of the engine to which the carburetor is adapted by being adjusted endwise. An operating link 31 is connected to the Venturi element and to an operating shaft 38. The operating shaft is adapted for connection with a conventional type of control or accelerator pedal (not shown) whereby the Venturi element may be slid in opposite directions in the mixing chamber and relative to the nozzle 26. The Venturi element 36 when positioned at the end of its movement in one direction, brings the restricted part of its passage into engagement with the face B of the nozzle 26 and thereby cuts off the air past the jets of the nozzle, the engine then receives high grade fuel from means to maintain operation thereof at idling speed an'd'which'will be hereinafter described indetail. The Venturi element on being the Venturi element is gradually moved farther from the nozzle, additional air. is admitted to the mixing chamberand anadditional amountof low grade fuel is obtained from the upper group of jets, consequently increasing the speed of operation of the engine. I As the restricted portion of the; Venturi element reaches a plane slightly above the upper group of jets the passage between the latter and the Venturi. element is restricted causirg thetinco ming air to create a.

suction in the upper group of jets which elevates the column of fuel in the tube 28 to overflow into the pot or recess134 and pass therefrom into the mixing. chamberbyway of the upper group" of jets; Thus it will be seen that as the Venturi element acting as a control valve, moves farther towards its. openposition an additional supply; of low grade fuel will be directed into the mixing chamber by the .upper group of jets over the supply of low grade fuel furnished by the lower group of jets. The incoming air is proportionately increased with the increase of the amount of incoming fuel so that a proper combustible mixture will be had for the engine operating. at speeds greater than idling speed, the air and low grade fuel being entirelycontrolled by the Venturielement acting as a throttle valve.. The Venturi element is equipped with a ring, similar the walls of the mixing chamber to effect a seal between the Venturi element and the walls of said mixing chamberand which compensates for expansion and contractionin these parts. The low grade of fuel-being preheated prior to reaching the nozzle will aid in the breaking up'of.

the fuelinto small particles as it passes from in construction to'a piston ringQwhich contacts the jets and as the wallsof the mixing chamber 3 are heated, these small particles of 1 low grade fuel become volatile and readily mix with, the

incomin'gair, producing an eflicient and economengine with the accumulation of carbon reduced to a, minimum.

A low grade fuel when discharged by'jets and subjected to heat will become volatile andcan be successfully elliploy d fdr tne opefation or an engine, while the speed of the engine is greater than idling s'peednewever, when the engine is operating at idling s'peed it should be furnished with a high grade 'of'fuel. cold engine it shouldstarted on a high grade fuel. Therefore, fiieaiis ben pfovided for introducing into the mixing chamber at the-time of the starting of engine a high grade fuel which will readily vaporize under atmospheric temperatures. This high grade fuel is also introduced into the mixing chamber during the operation of the engine at idling speed. This means consists of a float controlled bowl 411 suitably supported on the mixing chamber and fed in any well known manner with a high grade fuel. Connected on the bowl 4!! is a fuel pipe 4| having a control valve 42, preferably of the needle type. The control valve 42 is connected with the mixing chamber 43 for delivering therein a high grade of fuel from the bowl 4|]. The mixing chamber 43 or the lower wall thereof is in a plane slightly above the level of the fuel in the bowl 40, so that fuel may be drawn into the mixing chamber by suction from the engine, the amount of fuel being regulated by the needle valve 42. At this time the Venturi element has been brought into engagement with the face B of the nozzle cutting off the ordinary supply of air and the supply of low grade fuel. To place the mixing chamber 43 in communication with the mixing chamber of the carburetor a nozzle 44 is connected onto the mixing chamber 43 and extends into the mixing chamber I of the carburetor in the form of a curved tip 45, the free end of which is directed in the direction of the outlet of the mixing chamber A cutoff valve 46 is provided in the pipe 4|. The high grade fuel in a substantially raw state will be drawn into the engine to facilitate the starting thereof when cold. Connected to the mixing chamber 43 and located in a plane above the latter is an auxiliary air and fuel mixing chamber- 41 having control valves 43 and 49 for regulating a mixture of air and high grade fuel to the mixing chamber The auxiliary mixing chamber 41 is connected to the bowl 40 by a pipe 50. As soon as the engine starts on the high grade fuel as described it then draws air and high grade fuel into the mixing chamber by way of the nozzle 45 the latter receiving the air and high grade fuel from the auxiliary mixing chamber 41. Sufficient air and high grade fuel will be thus obtained for the operation of the engine at idling speed. As soon as the exhaust from the engine has heated the mixing chamber the Venturi element may be then moved towards an open position permitting the engine to draw into the mixing chamber I the low grade fuel so that the engine operates on the low grade fuel at all speeds except idling speed. As soon as the Venturi element moves towards an open position opening the main air supply to the mixing chamber suction will be discontinued on the nozzle 45 and thereby eliminate the high grade fuel entering the mixing chamber I. The auxiliary mixing chamber 41 is shown in detail in Figure 5 and it is" apparentthat es" Also starting a 1 open to the afimespneraw admit by the valve 48 while another eh V isconnete d to therung chamber- 43" and still .ancther end of its? passage-c ected to the bowl 4|lby"the'pi pe 50 and s aid'l'ast named end of its passage ofl'tl llefi the valve 49. Through the adjustment-s of the valves 48 and 49 a proper n iixfiui Of al i d e fil'l can-be had sustain oneratioaof the enzine at idlin sneecl.

,The amount of exhaust now through the stove 9' can to some degree be controlled by the valve- I5 and when the amount of exhaust is desired to be decreased the valve 15 is movedftowards an open position, so thats'eme of the exhaustcan pass from the as age |2- directly into the passage" 13. dl'l 111 031861300 rhuchheatis furnished for the heating of the mixing chamber.

Referring'to my modified form of the invention some of the operations referred to in connection with the form of carburetor shown in Figure 1 are cooperated in the modification except that the latter is arranged solely for the use of high grade fuel. The mixing chamber 5| thereof and the nozzle 52 are identical in construction to the mixing chamber 2| and the nozzle 25 also the Venturi tube 53 operates in a similar manner to the Venturi tube 36. Further, the mixing chamber 5| is heated by exhaust passing through a chamber 54 similar to the heating chamber 2. A float controlled fuel bowl 55 is supported by and in direct contact with the heating chamber 54 and receives in the ordinary manner from a supply a high grade of fuel. Connected to the bowl 55 is a pipe 56 which is in turn connected to the nozzle 52 whereby the fuel in the bowl 55 may seek a corresponding level in the nozzle 52. A mixing chamber 51 similar in construction to the auxiliary mixing chamber 41 is located in a plane slightly above the level of the fuel in the bowl 55 and is connected to the latter by a pipe 58. A pipe 59 connects the mixing chamber with an idling jet 60 located in the mixing chamber below the nozzle 52. A carburetor, as shown in Figure 9, when adapted to an engine will supply the latter with a high grade fuel properly mixed with air and preheated for the operation of said engine when operating under load. However, when the Venturi tube 53 is positioned for reducing the operation of the engine to idling speed sufficient fuel is then admitted to the mixing chamber by way of the idling jet 60.

What is claimed is:

1. A carburetor comprising a vertically arranged mixing chamber open at its upper end to the atmosphere, means connecting the lower end of said chamber to an intake manifold of anengine, a nozzle located in the chamber with the discharge end thereof disposed uppermost,

an exhaust stove surrounding the major portion of the mixing chamber and substantially the entire portion of the intake manifold, with said means arranged exteriorly of the stove and including an intake passage and an exhaust passage and a low grade float control fuel supply means engaging and supported by the stove and connected to said nozzle, and a high grade fuel nozzle connecting with the mixing chamber below the first nozzle and within the mixing chamber non-covered by said stove, a high grade fuel and air supply means connected to said second nozzle, and a manually actuated slidabl-e Venturi element in said mixing chamber-and movable end was passage ""r controlled: its passage from the second nozzle.

2. A carburetor comprising a vertically arranged mixing chamber open to the atmosphere at its upper end, means connecting the lower end of said chamber to an intake manifold of an engine, a nozzle located in the chamber with the discharge thereof including a pair of ports and jet passages arranged in superimposed relation, an exhaust stove surrounding the major portion of the mixing chamber and substantially the entire portion of the intake manifold and including an air intake passage and an exhaust passage having direct communication with each other adjacent the intake end of the intake passage, a valve for controlling the communication beengine.

tween said passages, a low grade float controlled fuel supply means engaging the stove to be heated thereby and connected to said nozzle, a high grade fuel nozzle entering the mixing chamber below the first-named nozzle, a high grade fuel and air supply means connected to said second nozzle, and a manually actuated slidable Venturi element in said mixing chamber and movable relative to the first nozzle for controlling the flow of air past said nozzle and the fuel from the jet passages thereof and may be brought in engagement with said first nozzle to out off the flow of low grade fuel from the jet passages and thereby permit high grade fuel to be obtained from the second nozzle by the suction of the FLOYD E. SIVHTH. 

